Final answer:
A durable memory system that can hold a vast amount of information indefinitely is known as long-term memory, the final stage of memory according to the Atkinson-Shiffrin model.
Step-by-step explanation:
A durable memory system with an immense capacity for information is known as long-term memory. It is the third stage in the Atkinson-Shiffrin model, following sensory and short-term memory stages. Unlike short-term and sensory memory, which have limited capacities and hold information temporarily, long-term memory can store unlimited amounts of information for extended periods, ranging from minutes to a lifetime. Long-term memory includes different types of memories, such as explicit (declarative) and implicit (non-declarative) memories.